Security is a key design challenge for most systems and applications. Attacks and unauthorized access to a system can lead to the loss of critical data, network downtime, and lost productivity and revenue. There is often a need to authenticate users and to protect network infrastructure and the associated users via private keys and certificates to provide security.
A Trusted Platform Module (TPM) that complies with the specifications published by the Trusted Computing Group (TCG) is a microcontroller security chip that may be used to defend the internal data structures against attacks. The TPM security chip ensures that the stored information, such as keys, passwords and digital certificates, is secure from external software attacks and physical theft by performing cryptographic functions on the chip. TPM may be integrated into the boot process to establish a trust level and to gather measurement about the running environment for trusted reporting. A TPM chip may be affixed to the motherboard of a computing system to provide this functionality.
The TPM chip stores keys, passwords and digital certificates. The nature of the device—i.e. a silicon-based microcontroller—ensures that the stored information is secure from external software attack and physical theft. Security processes, such as digital signature and key exchange, are protected through subsystems on the chip. Access to data and secrets on a platform may be denied, for example, if a system boot sequence is not as expected by the TPM chip. Critical applications and capabilities, such as secure email, secure web access and local protection of data are thereby made much more secure.
One limitation of TPM chips is an inability to expand or upgrade memory size if needed, for example, due to a new secure application, a change in the size of an existing secure application, or storage of additional secure data to be processed by the TPM chip. TPM typically has a passive role in a system. The TPM chip does not select what software it runs, but instead acts as a slave to higher level applications by storing and reporting pre-runtime configuration information. Typical TPM chips use their own internal firmware and logic circuits for processing instructions, and do not rely upon the underlying system.
Similarly, the Mobile Trusted Module (MTM) is a newly approved TCG specification for use in mobile and embedded devices. MTM originates from TPM v. 1.2, and introduces a secure boot concept. MTM also supports implementation as a functionality rather than as a physical implementation in hardware, which makes it possible for device manufacturers to add the MTM to already deployed, proprietary security solutions.